Preserve grim type of directness (7)
I believe the answer is:
candour
'directness' is the definition.
(I know that directness can be written as candour)
'preserve grim' is the wordplay.
'preserve' becomes 'can' (canning is a kind of preserving).
'grim' becomes 'dour' (synonyms).
'can'+'dour'='CANDOUR'
'type of' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for candour that I've seen before include "open)" , "Forthrightness" , "telling it like it is" , "Opening up" , "Frankness, openness" .)